Evaluation of the degress of hydrogenation of steel by acoustic analysis

• Published in: Materials science (New York, N.Y.) Vol. 33; no. 4; pp. 565 - 567
• Main Author: Agaev, N M
• Format: Journal Article
• Language: English
• Published: 01.01.1998
• ISSN: 1068-820X

Hydrogenation is quite often responsible for the deterioration of the physicomechanical characteristics of metals and alloys. In choosing corrosion inhibitors, this fact should necessarily be taken into account. Among the methods used for the evaluation of the degree of hydrogenation of metals, one should especially mention the acoustic method based on the analysis of the velocity of ultrasonic waves penetrating through metals. In the present work, we make an attempt to apply the acoustic method to the investigation of the absorption of hydrogen in the presence of various organic inhibitors. Specimens with a diameter of 34 mm and a thickness of 12 mm were made of steel with the following chemical composition: 0.14-0.19% C, 1.3% Mn, 0.15-0.4% Si, 0.8-1.1% Cr, balance Fe. They were subjected to cathodic polarization at a current density of 20 mA/cm exp 2 in the following mixture of acids: 1 N H sub 2 SO sub 4 +40mg/liter H sub 2 SeO sub 3 . Selenious acid was used as a stimulator. Specimens were preliminarily etched in a 32% HCl solution with an admixture of [CH sub 3 (CH sub 2 ) sub 3 NH sub 2 ]CS inhibitor, washed, dried, and placed into a cell between two piezoelectric crystals emitting ultrasonic waves. To improve acoustic contact on the surface of the crystals, we placed a drop of a special paste (Echotrace 9000 Couplant for Ultrasonic Testing).